Laboratoire des Interactions Moléculaires et Réactivité Chimique et Photochimique
UMR 5623

Séminaire par Carlos MARQUES

Vendredi 4 octobre 2019 - 14h30 - Salle Maroni / MHT

Carlos MARQUES, de l'Institut Charles Sadron de l'Université de Strasbourg, fera une présentation intitulée: "Alterations of lipid bilayers under photo-induced oxidation"

The optical absorption spectrum of lipids or of lipid membranes does not display any peculiar feature in the visible wavelength range, from 400 to 700 nm. A lipid bilayer can be thus observed under a light microscope for many hours without being destroyed, transformed or even without suffering any visible degradation. Light, however, can induce numerous chemical and physical transformations in real lipid membrane systems that contain often photosensitive molecules: fluorescently labeled phospholipids, cholesterol, proteins and other membrane-forming molecules, fluorophores added to the solution for measuring permeability and other properties, biomimetic constructs, including light-sensitive proteins embedded or interacting with the bilayer ... arguably most practical membrane systems strongly absorb light and bear thus the potential of undergoing membrane transformations when exposed to visible light.

In this talk I will discuss the physical transformations in lipid membranes exposed to photo-induced oxidation, a natural metabolic outcome of life with oxygen under light, but also a salient oxidation reaction in photomedicine treatments. After summarizing our recent efforts to understand alterations of lipid membrane structure, mechanics and phase behavior following the formation of photo-induced lipid products I will highlight current and future challenges for the physics of oxidized lipid membranes.

REFERENCES

A comprehensive review of this area can be found in “Shining light on membranes”, Chapter 22 of The Giant Vesicle Book, (Ed. R. Dimova and C. Marques), CRC Press 2019.

2019 IMRCP